Referring now to FIG. 1, a functional block diagram of an exemplary broadband system according to the prior art is depicted. A service provider 100 communicates with the Internet 102. The service provider communicates with first and second modems 104-1 and 104-2. End users connect routers 106-1 and 106-2 to the modems 104-1 and 104-2, respectively. Users then connect computers 108-1 and 108-2 to the routers 106-1 and 106-2, respectively. The users have Service Level Agreements (SLAs) with the service provider 100 that define their terms of service, including bandwidth limits. The service provider 100 programs each of the modems 104 with allowed bandwidth rates using a mechanism such as DOCSIS (Data Over Cable Service Interface Specification). In this way, each traffic flow arriving at the service provider 100 is rate-shaped by the respective modem 104.
In a direct broadband system, such as is widely deployed in South Korea, computers and/or routers connect directly to an Internet Service Provider (ISP) 150, as depicted in FIG. 2. The ISP maintains a connection to the Internet 152, and communicates with routers 154-1 and 154-2. Computer 156-1 is connected to router 154-1, and computers 156-2 and 156-3 are connected to router 154-2. Computer 156-4 communicates directly to the ISP 150. In this example, none of the traffic arriving at the ISP 150 is rate-shaped, and therefore may arrive at full line speed (e.g., 100 Mbps). Users transmitting at full line speed may use so much bandwidth that the quality of service for other users is diminished. The ISP 150 would like to be able to apportion available bandwidth among the users, possibly offering higher levels of service (such as greater bandwidth) for increased fees.
Referring now to FIG. 3, a functional block diagram of an exemplary Internet Service Provider (ISP) network is depicted. The ISP 200 may service a number of users 202-1, 202-2, 202-3, . . . , and 202-m. The users 202 communicate with edge routers 204-1, 204-2, . . . , and 204-n. The edge routers 204 typically communicate with core routers 206-1, 206-2, 206-3, and 206-p . . . . Core routers 206 interconnect with each other and possibly communicate with the Internet 208, as core routers 206-2 and 206-3 do in this example.